1. Field of the Invention:
This invention relates to an improved reaction vessel for a high pressure/high temperature belt type apparatus. This invention also relates to any type of high pressure apparatus wherein substantial extrusion or deformation of gasketing material occurs. More particularly, this invention relates to use of low shear strength materials that undergo pressure-induced phase transformations that can be employed in combination with other low shear strength materials to minimize the distortion of reaction vessel components that conduct electrical current for the purpose of generating heat and to minimize the distortion of as-pressed polycrystalline diamond compacts.
1. Description of the Art
In general, a reaction vessel may be described as a vessel or capsule within which there is positioned a given specimen material to be subjected to high pressure/high temperature conditions for research study or for manufacture of useful materials or articles. Similar prior art reaction vessels of the belt type and the cubic type have been described in numerous patents and, more specifically, in U.S. Pat. Nos. 2,941,241 to Strong; 2,941,248 to Hall; 2,992,900 to Bovenkerk; and 3,088,170 to Strong, together with suitable apparatus for the application of the pressures involved.
Ordinarily, an ultrahigh pressure/high temperature reaction vessel is adapted to undergo considerable deformation; e.g., when placed in a confining apparatus or enclosure, such as a defined belt or chamber, and then subjected to compression by suitable moving members. The distribution of pressure in reaction vessels of this type is the subject of a U.S. Pat. No. 3,030,662 to Strong. This patent discusses the use of low shear strength materials for the purpose of transmitting substantially hydrostatic pressure to the inner two-thirds to four-fifths of the reaction vessel. Although the patent states that mixtures or combinations of various low shear strength materials can be employed and can also be used in combination with suitable high strength materials, it does not provide a solution to the problem of distortion or dislocation of essential reaction vessel components during compression to high pressures.
More recently, the problem of obtaining precise control over the temperature caused by the deformation of the end assemblies of such high pressure/high temperature reaction vessels was the subject of the Applicant's co-pending U.S. patent application Ser. No. 07/660,332, filed on Feb. 22, 1991, and entitled "MODIFIED END ASSEMBLY FOR HIGH PRESSURE, HIGH TEMPERATURE REACTION VESSELS". However, the substantial outward extrusion of the gasketing that occurs during compression results in unwanted deformation of still other critical internal reaction vessel components, thus affecting the uniform distribution of both pressure and heat throughout the vessel.
Accordingly, an improved reaction vessel is desirable wherein the internal components are not significantly distorted during compaction at ultrahigh pressures in a belt or cubic type high pressure apparatus.